Synchronizing Structure of Maven and IntelliJ IDEA Projects

On pressing this button, IntelliJ IDEA parses the project structure in the Maven tool window.

Note that if you configure a dependency through the Project Structure dialog, the dependency will only appear in the IntelliJ IDEA Project tool window, not in the Maven tool window.

Alternatively, open Maven Settings and select the Import Maven projects automatically check box. In this case, IntelliJ IDEA will reimport Maven projects automatically every time you change the pom.xml.